This invention relates to drain closures which serve primarily to open and close the drains of bathtubs but which can also be used in sinks, laundry tubs and the like.
Bathtub drain closures are of two basic types; i.e., trip lever and non trip lever. The trip lever device consists of a closure connected by means of a linkage system to a trip lever handle mounted on the front end wall of the tub. The closure is opened and closed by raising or lowering the trip lever handle. The non trip lever closure requires direct contact with hand or foot to open and close.
The main purpose of the present invention is to combine into one closure the advantages of nontrip lever hand and foot operated closures while at the same time eliminating the disadvantages. Another purpose is to provide a stopper which is interchangeable with other stoppers in foot operated closures.
Foot operated closures are opened and closed by pressing down with a foot on the stopper portion of the closure, as described in U.S. Pat. Nos. 3,771,177 and 4,103,372. The principal advantage claimed over hand operated closures is that the user does not have to bend over to operate the closure.
In reality, it is only the ability to close the closure without bending over that is a meaningful advantage. The reason is that, with rare exceptions, the closure is closed only when the user takes a bath which is invariably done in a sitting position. After completing the bath, it is as easy to first open the closure by hand and then stand up and vacate the tub as it is to first stand up, open the closure by foot and then vacate the tub. Therefore, the ability to open a tub closure by foot is of minimal value to most users.
The foot operated closures that are now available have several significant shortcomings. The first is that, due to the necessarily more complicated design, they are less reliable and fail more often than hand operated closures.
Another disadvantage of some foot operated closures is that the closure is susceptible to damage by guests in hotels and motels. Specifically, foot pressure on one side of the stopper is required to open the closure while foot pressure on the opposite side is required to close. Adding to the problem is the fact that the location of these two pressure points will vary from tub to tub depending upon how tightly the stopper assembly is threaded into the tub strainer body. Although the open and close pressure points are marked on the stopper top, these markings are not legible to most while standing up due to poor lighting in the tub bottom and go unnoticed by others. As a result, some guests not familiar with this type of closure, will step down several times without results, becoming convinced that the closure is stuck, and then step down with excessive force or give the stopper a kick to free it up. Damage to the closure can and does occur along with an occasional bruised foot.
A third disadvantage is the ease with which the stopper assembly can be removed and stolen. The stopper assembly is typically installed by threading the post portion of the stopper assembly into female threads located in the bottom of the strainer body. This is accomplished by hand. Further tightening by a pair of pliers or a wrench is normally not done since the application of pressure on the plastic stopper by pliers or a wrench can cause it to crack or flex enough to break the bond between the plastic and the chrome finish. Therefore, it is relatively easy for most people to remove the hand tightened stopper assembly. Unfortunately, some guests in hotels and motels do just that, as do vandals roaming through unfinished housing projects.
As a direct result of this security problem, one manufacturer of foot operated closures has offered a theft resistant model. However, this design has three distinct disadvantages: (1) it costs substantially more; (2) the theft resistant stopper requires a special strainer body and will not fit any other strainer body; and (3) a special tool, available only from this manufacturer, is required to remove the stopper.
Hand operated tub closures are most often a type commonly referred to as lift and turn or lift and lock. In this type of unit, the metal stopper stays in the down position due to its own weight. To open, the stopper is lifted up and then turned in either direction. This rotation positions a small pin over a shoulder on either a post or sleeve and thereby holds the stopper up in the open position.
Lift and turn closures have advantages over foot operated closures in several important respects. The lift and turn closures are much simpler, require fewer moving parts, and are not plagued by field problems to the extend that foot operated closures are. In addition, the lift and turn closures can be made entirely from metal (except for the neoprene seal used by some), as preferred by many plumbers.
The disadvantages of lift and turn closures vary with individual designs. By far the most popular is one which incorporates a metal post that moves up and down inside a sleeve attached to the bottom of the strainer body. The bottom of the post has a retainer ring which prevents the post from being pulled completely out of the sleeve. A small peg or pin protrudes from the post. This peg fits in a slot in the upper portion of the sleeve and prevents the post from turning when in the down or closed position, thereby permitting the stopper to be threaded onto the top end of the post. When the stopper is lifted and rotated, the peg is positioned over the top of the sleeve and holds the stopper in the open position.
One disadvantage of this type of closure is that the stopper can be easily stolen. Only moderate pressure with a tool can be used to tighten the stopper onto the post to avoid breaking the peg. Accordingly, the stopper can be removed relatively easily from the post by thieves and vandals. Another disadvantage is that the peg can be broken if a sharp blow is applied to the top of the stopper while it is in the up or open position.
Another lift and turn design features a post with a flat on one side attached to the bottom of the strainer body. A brass set screw located out of sight is threaded through an integral collar on the bottom of the stopper. The end of the set screw projects beneath a head on top of the post and thereby holds the stopper on the post. When the set screw is aligned with the flat on the post, the stopper drops to the closed position. However, when the stopper is lifted and turned to move the set screw out of alignment with the flat, the set screw rests on a shoulder to hold the stopper up in the open position. Although the problem of stopper theft is virtually eliminated in this type of unit, several other problems are created. A blow applied to the stopper while in the up (open) position can bend the end of the set screw, thus making it impossible to back the set screw off to permit removal of the stopper when it is necessary to obtain access to the drain. Corrosion of the threads on the set screw or collar caused by prolonged exposure to moisture can likewise make it difficult to back off the set screw. Even if the set screw is not damaged or corroded, its out of sight location makes it necessary to locate its head by feel, i.e., by applying the finger to the bottom of the stopper until the head of the set screw is located. This is difficult at best and may be impossible for persons with large fingers. Also, the type (phillips or regular) and size of screw driver to use for loosening of the set screw is not known to persons unfamiliar with this particular closure.
Another lift and turn closure features a plastic skirt attached to the bottom of the stopper. The exterior of the skirt has vertical and horizontal grooves which receive two bosses punched into opposite sides of the top vertical wall of the strainer body. Stopper theft can be easily accomplished simply by pulling up on the stopper and continuing to rotate it. Another disadvantage is that a sharp blow to the stopper top can cause damage to the plastic skirt or cause the bosses and grooves to disengage and thereby jam the closure.
All lift and turn closures have one common disadvantage compared to foot operated closures--they cannot be closed without bending over and operating the closure by hand.
Still another non trip lever closure is best described referred to as a push-pull. It operates the same as a lift and turn closure except that no rotation of the stopper is required in order to keep the stopper open in the up position. The push-pull stopper features one or more rigid plastic legs that are deflected to install the stopper. The main disadvantage of this design is that a sharp pull upward is all that is required to remove the stopper. Another disadvantage is that the plastic legs are relatively fragile as compared to metal and are susceptible to fracture. A plastic construction is necessary because of the need for the legs to deflect. As a result, this design is generally unacceptable.